cummer



(No Model.)

1:". D. CUMMER. PROCESS 0F DRYING AND DISINTEGRATING CLAY, 50.

No. 482,823. Patented Sept. 20, 1892.

ffn c. JJ e ai UNITED STATES PATENT OFFICE,

FRANKLIN D. CUMMER, OF CLEVELAND, OHIO, ASSIGNOR TO ELIZA E. CUMMER, OF SAME PLACE.

PROCESS OF DRYING AND DISINTEGRATING CLAY, 800.

SPECIFICATION forming part of Letters Patent No. 482,823, dated September 20, 1892.

Application filed July 25, 1891. Serial No. 400,744. (No specimens.)

To a/ZZ whom it may concern:

Be it known that I, FRANKLIN D. CUMMER,

of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Processes of Drying 'and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

My invention relates to a new process of drying and disintegrating clay and similar material; and it consists in the steps hereinafter described and claimed.

As is Well known, the clay for manufacturing porcelain, china, and the finer goods generally is treated in a lilter-press; but such treatment is too expensive for manufacturing pressed brick, flower-pots, and other coarser goods, and for such coarser goods it is desirable to dry the clay if it can be done cheaply, because, among other reasons, the clay when dry can be screened to remove small stones and other impurities which could not well be removed by the Wet process.

It is generally understood that potters clay -cannot be heated above 250O Fahrenheit withjout injuring its adhesive qualities, thus rendering it unt for pressed brick and pottery purposes. On the other hand, the process of drying clay exposed to a temperature less than 250 Fahrenheit would be so slow and 'expensive that it would usually be considered impracticable. Besides,A such slow process would be likely to bake the material into hard masses diftcult to reduce so as to be t for use. I have found means for drying clay quickly and cheaply, and at the end of the process the clay or other material is in condition slaked or disintegrated and mellow, like an ash-heap, and consequently ready for screening or further reduction.

In preparing clay for treatment by my improved process substantially the same means may be employed as in preparing the clay for the Wet process, to wit: The clay as it comes from the clay-bank is passed between claycrushing rollers, Where the large stones are removed and the smaller stones are likely broken in passing the rolls. The clay issues from the rolls in the form of a sheet, and this sheet of clay by means of pickers or Whippers is preferably broken into small pieces-say the size of the end of a persons finger and smaller. In such condition the clay is subjected to my process, which is as follows: The first stage of the process comprises the roasting of the clayAthat is to say, subjecting the clay to a high degree of heat-meantime preferably stirring the clay constantly and thoroughly. The best means that I know ot for this purpose is an inclined rotating cylinder, the material being fed into the upper end of the cylinder and being discharged at the other end, the cylinder being provided with such internal ribs, projections, or depressions as will carry up the material with the ascending side of the cylinder and scatter the materials down as evenly as may be across the diameter of the cylinder. The firing is done under the upper end of the cylinder, and the products ot' combustion after passing rearward along1 the under section of the cylinder between the side walls of the setting is returned through the cylinder, where it comes in contact with the material. The cylinder may be heated red-hot without injuring the clay, so long as there is any considerable moisture in the clay that is being evaporated, and such escaping vapors will carry oft the surplus heat in excess of the evaporatingpoint--say2l2j Fahrenheit. \Vhen,however, the clay becomes partially dry, so that but little vapor escapes therefrom, care must be taken not to overheat the clay, and at such point the clay should be discharged from the cylinder, and to this end the cylinder may be revolved slower or faster, and also the clay may be fed slower or faster, for it is evident that if a large amount of clay be passing the cylinder during a given time it Will not become heated to so high a degree as if the quantity was small. vThe object sought is to dry the clay, so far as may be, in the cylinder without injuring it, and at the same time to heat the clay enough so that after it is discharged from the cylinder and placed in piles or bins in large quantities the aggregate heat in the mass will bev sutlicient to evaporate, the remaining moisture .and complete the drying process. The heated material after it has been placed in largepiles or in bins is left for a time to cool down. The moisture eX- pelled during the cooling-down stage renders the-material exceedingly friable, andthe slaking or disintegrating of the clay during the cooling stage will leave a large share of the clay mellow, like an ash-pit, ready for screening or for other separationl intoV dierent grades of lineness suitable for use in making different qualities of Ware. InV passing the material over screens the small=` stones and similar impurities are readilyremoved, andif there should remain some lumps of clay that haveA not been thoroughly slaked theseareeasilypulverized by tumblingorfotherfmeaua so that withlittle trouble the clay freedl from tionwith more especially the fine screens, .an

air-currentl be employedto carry oti 'the dust suchdust willbe found to `be substantiallyas; fine as the product fromthe same material r,

had through a tilteringfpress.

Another advantageof thedryprocess con ductedas aforesaid isthat manyimpurities found inthe clay-such for instanceas sulphur, arsenic, &c.are volatilized and thus: disposed of in heatingor roasting the clay such volatile matterof course passingo with the vapor from the dryingclay.

In the accompanying drawings is. shown suitable means for carrying outmy improved ,A during the drying process in the machine will process, although I do not wish to limit my-N self to any particular mechanism for the reason that any mechanical drierfthat willlkeepthe material constantly and thoroughlystirred answer the purpose.

Figure 1 isa View in perspective of adry-` ing apparatus. Fig. 2 is a view in perspective of a pile of material supposed to `have been passed through the drier and leftf, for cooling.

The material is fed into hopper or spoutA and from thence passes into the inclined rotating cylinder B, the material' -being discharged at the rear end through spout D. T-he l firing isdone under the front end of the cylinder, and the products of combustionpass rearward under the cylinder between the side walls of thesetting and from thence return through the cylinder, of course in the opposite direction from that taken by the material, the gases and the vapor from the materialpassing off through chimneyG. I. may remark 4that an applicationfor United States Letters Patent fora drier of this construction; has alreadyT been made the subject ofan application for Letters Patent byme and is nowpend-` ing in the Patent Office; but,4as aforesaid, I

ing the material such bins should be provided with means for ventilation at the sides as well as at. the top, so that the vapor escaping from the mass of material can pass oit freely. Sometimes the clay or other material is of such a wet sticky nature that it will adhere to the heated `cylinder as soon as itcomesin contact therewith. In such case I provide asmall elevator of soniekind-forinstance,asat H. This elevator takes up a small quantity of: the heatedrmaterial dischargedfromspout Dand discharges 1t into hopperA, where it .mixes with the rawmate'riaLand serves the samev purpose as sprink- `fling our oyerA dough inthe culinary, departy :ment--Y-that is to say, itrenders it lessstick-y;

also, there maybe placed a thermometer I in such position that it is im pinged by the hotmaterial being discharged into the hopper, and by watching this thermometer the operator can tell whether the materialdischargedfrom the .drierfis or is not atthe properftemperature and can. regulate his tire, `feed, &c., accordingly. Where this returningof material to mixwith the raw. material is not required, I may add that in regard'to the precisecondition of the partly-dried material whereit should-be dis- .chargedlfrom the machinea little practice `will enablea person of` intelligenceto determine thisby observing` the amount of vapor l passingifrom the material atforinear the/point `ofdischarg.eandso longas any considerable lamountf` of vapor. is seen passing off from-the Lmaterial no fears may. be had that the material is being overheated; but when little vapor .isseen escaping from the-materialit maybe assumed that ,there isenough heat in the material to `complete .i the dryingafter-the material hasv been piled. `As a.. matter of fact, I

t) l l l IOO IIO

`will state that Indlnodifticulty inrunning .ten tons of4 materialper hour through a drier,

such material being discharged from the drier in` such heatedand partially-dried cou` dition `that the drying is completedy in the ypilesof material, from which it will be understood that my improved process lis` comparativelycheap.

1.. The processfhereindescribed of.l drying clay and similarfmaterial, `andzconsisting, essentially, first, in heating and stirring the ma terial until it is partially. dried, and, second,

piling the heated and partially-dried material, wherebythe dryingfprocessis-completed by. meansof, the aggregate heat in the pile of materiahsubstantially as set forth.

2. The process hereindescribedof drying clay. and similar materials, comprising, first, heating,. stirring, andpartially drying, the

material in any suitable mechanical drier; In testimony whereof Isign this specificaseeond, returning a portion of the heated mation, in the presence of two witnesses, this 22d 1o terial and mixing it with Ithe green material day of June, 1891. to be heated, and, third, piling the heated and L; partially-dried materialto evaporate the same FRANKLN D' CUMMER to dryness by means of the accumulated heat Witnesses: in such pile of material, substantially as set C. H. DORER, forth. WARD HOOVER. 

